Traditional saw-blade height adjusting devices for woodworking table saws generally have complex structures, and are generally difficult to operate which results in excessive labor and time consumption. Users of the traditional table saws face a lot of inconveniences, including that the height of the saw blade cannot be adjusted easily and promptly when desired, or in other words, it is difficult to adjust the cutting-in depth of the workpiece. Difficulty in adjusting the height of the saw blade also results in a low output of the table saw. Meanwhile, for their complex structures, the manufacturing cost of the table saws is also high.